How A Lack Of Sleep Makes You Fat

Sleep deprivation could be making you fat, and a new study has found out how.In the new paper, publishing tomorrow’s issue (Oct. 16) of the journal Annals of Internal Medicine, researchers have found that not getting enough sleep affects your metabolism by disrupting the way your fat cells respond to insulin, the hormone that makes them take up sugar from the bloodstream.

The researchers, led by Matthew Brady of the University of Chicago, studied seven volunteers after changing their sleep conditions: either eight and a half hours in bed, or four and a half hours. They were kept in each condition for four consecutive nights.

After the fourth night, a glucose tolerance test was performed by collecting fat from above the belly button. The fat was incubated with a glucose containing solution then stimulated with insulin.

The researchers looked for the ability of insulin to turn on the insulin signaling pathway, a signal of insulin sensitivity. A reduction in insulin sensitivity is seen, and thought to be the culprit behind, metabolic syndrome and type two diabetes.

They found a 30 per cent reduction of insulin sensitivity in the fat cells of the sleep deprived subjects. This reduction is in the same range of the reduction seen in obese and diabetic individuals. This could be how sleep deprivation is linked to obesity.

“Many people think of fat as a problem, but it serves a vital function,” Brady said in a statement from the University. “Body fat, also known as adipose tissue, stores and releases energy. In storage mode, fat cells remove fatty acids and lipids from the circulation where they can damage other tissues. When fat cells cannot respond effectively to insulin, these lipids leach out into the circulation, leading to serious complications.”